Vladimir Putin’s Russia is willing to take action against other states that “any other nation would see as completely unacceptable,” Williamson claimed.

“The plan for the Russians won’t be for landing craft to appear in the South Bay in Scarborough, and off Brighton Beach,” said Williamson, who Theresa May appointed defence secretary in November 2017.

“What they are looking at doing is they are going to be thinking ‘How can we just cause so much pain to Britain?’ Damage its economy, rip its infrastructure apart, actually cause thousands and thousands and thousands of deaths, but actually have an element of creating total chaos within the country.”

The Kremlin is spying on Britain’s key infrastructure and thinking “How can we hurt Britain?” he added.

Russian officials have responded to his remarks with derision. “What is really stunning is this: if Williamson in this way hopes to draw attention to his own personality, he is not the first one in the defense secretary’s seat who is trying to score political points by spooking the British people with horror stories,” Konashenkov said.

“But if it is Britain’s General Staff that reports such nonsense to him, then he should start thinking not about ways of increasing the defense budget but checking British military planners for professional aptitude, with a special emphasis on medical exams.”

“Defense Secretary Gavin Williamson said that under the influence of having just read Herbert Wells’ novel The War of the Worlds, which describes the invasion of Martians into England,” said the deputy chairman of the Russian parliament’s upper house’s defence and security committee.

“It’s a carbon copy, the only thing that is missing are the heat rays used by the aliens to destroy everything around them.”